The Friden EC-130 from 1964 was one of the very first all-transistor electronic calculators. The circuitry was built entirely with discrete components, with internal storage provided by a mechanical delay line memory. The calculator used "reverse Polish" notation, with the four stack registers visible simultaneously on a cathode ray tube display.

The EC-132 from 1965 was basically identical to the EC-130, but with the addition of a square root function.

The machine illustrated was purchased in 1966 by the Australian Mineral Development Laboratories, at a price in the thousands of dollars. It was obsolete and sold for scrap within three years.

The Bell Punch Company of England is generally credited with building the first production electronic calculator - the ANITA - in 1962. This 10-key Anita Model 1011 was made in England in early 1970, using discrete-component diode and transistor logic and a small number of MOS integrated circuits.  More...

The AL-2000 is a very early programmable desk calculator, introduced by the Casio Computer Co Ltd of Tokyo, Japan, in November 1969. The machine uses a mixture of discrete-component and integrated-circuit diode-transistor logic, and contains two special MSI (medium-scale integration) MOS chips. A magnetic core memory module from Mitsubishi provides 512 bits of memory (yes, bits) for the working registers and the program.  More...

This "Swedish" Facit 1135J was built by Sharp in Japan in 1971, using a set of seven MOS-LSI chips from Rockwell in America, on boards which appear to have been assembled by Canon. The machine has three memory registers accessed through the keys on the right-hand side, and includes a square root function. The design is generally similar to the Sharp "Compet" machines of the time.  More...

The manufacture of electronic printing calculators was made possible by the introduction of the low-cost EP-101 impact printer from Shinshu Seiki Corporation (later to become the Epson Corporation) in 1968.

The Facit 1148 appears to be a more refined version of the Sharp CS-743R from early 1973. The calculator has no numerical display, but prints all entries and results on a 15-column EP-104 impact printer. (The lower section of the case has mountings for the original EP-101 printer, but this machine has the smaller EP-104 mounted on an elevated platform). The processor uses two MOS-LSI chips from NEC, with five support chips and a host of discrete components. The keyboard uses separate mechanical key switches mounted on a circuit board in a metal frame.

When performing addition and subtraction the calculator operates in the same manner as the long-established mechanical adding and listing machines. Values are printed as they are entered via the add and subtract keys, and results are obtained with the (separate) total and sub-total keys. Entries or results can be added to (or subtracted from) the memory register, and retrieved with similar total and sub-total functions. A switch setting allows currency amounts to be entered without using the decimal point key.

Internal view (29kb)
Epson EP-101 printer description

The Computer Design Corporation of Los Angeles built a range of advanced desktop and portable calculators in the early 1970s.

This Model 155 "Surveyor" is a programmable scientific desk calculator using MOS-LSI logic. It provides scientific notation, trig and log funtions, powers and roots, ten storage registers, register arithmetic, and a number of special functions of interest to surveyors.

The calculator has no numeric display, but prints all entries and results on an internal 21-column impact printer. When programming, a set of eight neon lamps provide an octal display of the contents of the program counter or the instruction register.

This machine was donated to the museum by John B White Pty Ltd, Consulting Surveyors, of Sydney, Australia. It was purchased new in 1972, and was used regularly for survey computations until replaced by programmable pocket calculators in around 1979.  More...

The Compucorp "Alpha 325 Scientist" is a programmable scientific desk calculator with a numeric display and an internal printer. It provides all of the standard functions of the earlier 100 series, plus some statistical functions and English/Metric conversions. The machine operates with 13-digit precision, with a worst-case error (on trig and log functions) of less than one part in the 11th place.

The Model 325 has an advanced programming capability which includes labels, nested subroutines (six levels), and conditional branching. Programs and register data can be stored as files on a Model 392 cassette tape drive, which attaches via a single DB-25 connector. The tape drive can be controlled from within a program, allowing the machine to automatically load program overlays and handle significant quantities of data.

The circuitry has been reduced to three small boards (90 x 180mm) in the base of the machine, with a larger keyboard and display driver board in the top section. There are five 40-pin chips on the CPU board, 2 on the keyboard and display board, and one on the printer board. The memory board has four 28-pin program ROMs and eight Intel 2102 (1k x 1) static RAMs.

The Model 325 was supplied with a comprehensive 200-page reference manual (dated 1974), and has a pull-out quick-reference card under the keyboard.

The machine illustrated was originally used for programmed statistical calculations at an Australian university.

With 392 tape drive (25kb)
Internal view (26kb)
Operator's view (58kb)

The Victor Comptometer Corporation sold a range of attractive and functional desktop calculators under the "Victor 1800" label from around 1971.

The machine illustrated is a "scientific" model that was built in mid-1973. It provides trig and log functions and their inverses, powers, square roots, and reciprocals. It operates in degrees or radians, and in common or natural logarithms. There is a single (accumulating) memory register.  More...

The Burroughs C5155 is a basic four-function desk calculator from 1973. The circuitry uses three 40-pin MOS LSI chips from AMI, plus a host of supporting components.  More...

Texas Instruments built the first of their single-chip MOS-LSI calculator processors (the TMS-0100 series) in 1971. As these devices became commercially available and prices rapidly fell, it became possible for just about anyone to build an electronic calculator. This TE8000 is a "no-name" four-function machine using a TMS-0105 single-chip processor from 1973.  More...